Dr. Hannah Gay, the doctor who treated the child who has been deemed “functionally cured” of HIV, says the discovery surprised her.

Scientists on Sunday stunned with the announcement that a child treated with an antiviral drug cocktail shows no sign of harboring the virus that causes AIDS.

The baby's mother was not diagnosed with HIV until she was in labor. Doctors gave the baby a stronger and earlier treatment than usual starting within 30 hours of birth, before the child had been diagnosed as having acquired HIV from her mother.

She was taken off medication about a year ago and the virus did not rebound.

Dr. Hannah Gay, the associated professor of pediatrics at the University of Mississippi Medical Center who spearheaded the team that treated the child, said in an appearance on CNN that the results at first frightened her.

“I was very much surprised, almost in a panic,” Gay said. “Because my first thought was, 'Oh my goodness, I've been treating a child who is not actually infected.'”

“We're calling it a functional cure because we don't know yet what will happen to this baby. We're following the baby along and hoping that she'll go for the rest of her life without a reappearance of virus. However, there's a possibility that the virus may reappear. It may be in what we call viral reservoirs, or what I call for my patients hiding places.”

(Watch the entire segment at CNN.com.)